Critical renovascular disease (RVD) in the elderly may contribute to renal insufficiency by causing renal ischemia. Additionally, the hypertension associated with critical RVD may increase the risk of coronary heart disease (CHD) and stroke. However, the actual contribution of critical RVD (defined as greater than 60% diameter- reducing renal artery stenosis or occlusion) to these important health issues is uncertain because the prevalence of RVD in the elderly is unknown. Meaningful prevalence estimates have been limited by the absence of suitable screening methods for critical RVD and by the absence of accurate data obtained in population-based cohort. Specifically, this project proposes the use of renal duplex sonography (RDS) to detect the presence of critical RVD. This non-invasive ultrasound technique allows rapid and accurate evaluation of critical RVD. RDS will be applied to the Forsyth County, North Carolina cohort from the ongoing NHLBI- sponsored Cardiovascular Health Study (CHS), a longitudinal population- based study of CHD and stroke in elderly men and women. As a four year ancillary proposal to CHS, the prevalence of critical RVD and its association with renal function, subclinical cardiovascular disease (i.e., carotid ultrasonography, echocardiography), CHD and stroke will be characterized during the first two years of the project. In the last two years, the incidence of CHD, stroke and subclinical cardiovascular disease in the CHS participants demonstration critical RVD, with and without renal insufficiency, will be characterized. The application of RDS to the CHS Forsyth County cohort provides a unique opportunity to estimate the true prevalence of critical RVD in this elderly population. RDS results in combination with demographic data and analytic measurements made as part of the CHS will achieve the specific aims of this project without the need for additional evaluation. As a result, unique information pertaining to important health issues in the elderly will be obtained in a cost-efficient manner. This information will provide rationale for further investigation to examine new strategies or medical and interventional management of critical RVD in the elderly.